In this context, FLchain comes as a strong alternative to decentralize the classical FL process by allocating global model computation directly to each device without the need for any centralized server. Particularly, FLchain provides unique security features for the FL training offered by immutable blockchain, which thus enables reliable intelligent decentralized edge networks. The proposed FLchain architecture is shown in Fig. REF , including a group of MEC servers and distributed devices in a connected blockchain network. Due to the high computational capability, MEC servers are often selected to perform mining to maintain the blockchain network, while mobile devices can participate in local training or mining, or implement both training and mining tasks [1]}. The general FLchain procedure is summarized via the following steps.
